The present invention relates to improvements in cultivating implements, particularly for but not limited to crop row cultivation.
Conventionally, land for crop growing is cultivated, i.e. prepared for planting, by sequential use of various forms of ploughs and harrows often over a period of several weeks or more. Often a farmer may have more than one tractor to use the various implements for preparing land for crop growing. Further, the use of conventional equipment, while being effective to prepare the land cultivated to a certain depth, does often have an adverse effect on the earth beneath the cultivation zone. This lower level earth can become compacted through multiple passes of tractors using such conventional equipment, adversely affecting water flow patterns through the earth and in some cases increasing the likelihood of soil erosion.
A novel form of soil cultivating equipment is disclosed in Australian Petty Patent No. 656509. This specification discloses soil cultivating equipment having a pair of counter rotating discs each being generally horizontal but being higher at the front relative to the rear with respect to the direction of cultivation. Each of the discs has depending earth working blades circumferentially spaced from one another and arranged in sets with the blades of one set being inclined to the direction of rotation of the disc so as to have a forward cutting action and the blades of the second set being oppositely inclined so as to have a backwards cutting action. This specification also discloses the earth working blades of each set being positioned at different distances from the axis of rotation of the disc. It has been found that apparatus constructed in accordance with Australian Petty Patent No. 656509 does not operate satisfactorily as described in the specification.
An objective therefore of the present invention is to provide improved soil cultivation equipment generally of the type disclosed in the aforementioned patent specification but which is effective in operation. Further preferred objectives include providing soil cultivation equipment that may fully prepare a soil area for crop or other seedlings in a much quicker time than is possible utilising conventional machinery, and further avoiding the need to use multiple passes with different implements such as ploughs and harrows and of course multiple tractors for using such implements. A particularly preferred objective is to provide soil cultivation apparatus that may be used to prepare soil regions in spaced rows separated by uncultivated land zones (that is, so-called minimum tillage equipment) whereby only the land region required for crop growing is cultivated rather than the whole area of land. This is particularly useful for such crops as sugar cane but could of course be used in many other applications.
Accordingly, the present invention provides soil cultivating apparatus including a frame supporting at least one rotary cutting assembly having a plurality of earth working implements spaced around a peripheral region of a rotary support member mounted for rotation about a central upright axis of rotation, each said earth working implement being downwardly depending from said support member and having a primary cutting edge extending upwardly and rearwardly from a lower soil engaging extremity thereof, said earth working implements being arranged in separate sets where the primary cutting edge of each said earth working implement of a first said set also extends outwardly relative to a circumferential line traversed by the lower soil engaging extremity of the earth working implements of said first set, and in a second said set of the earth working implements, the primary cutting edge also extends radially inwardly relative to a circumferential line traversed by the lower soil engaging extremity of the earth working implements of said second set, the lower soil engaging extremity of the primary cutting edges of the earth working implements of the second said set being located at a radial distance from the central upright axis greater than the radial distance of the lower soil engaging extremity of the primary cutting edges of the earth working implements of said first set, said central axis of rotation being tilted relative to a forward direction of movement of the soil cultivating apparatus whereby a front region of the rotary support member is always maintained at a level higher than a rear region of the rotary support member.
Further preferred aspects and features of this invention are as defined in the claims annexed hereto which are incorporated in this disclosure by this reference thereto.
Soil cultivation apparatus according to this invention and/or preferred aspects thereof enable soil areas to be cultivated ready for crop planting with one pass of the apparatus even if the soil area had not previously undergone any form of preparatory work. Accordingly, the long periods of time for ground preparation using multiple passes of different implements such as ploughs, harrows and the like are no longer required. Further, the variation of different implements such as ploughs and harrows are also no longer required.
Still further, since the cultivation intensely works the earth or soil to a required depth but not below this depth, the ground conditions below the cultivation zone remain substantially unaffected by the cultivation process.